Improvement in hinge-joints for school-desks



Patented April 13,1875.

WITNESSES THEGRAFHIC CQ.PHOTO.-L|TN-39&41 PARK PLAG JLY- CHARLES H. PRESBREY, OF STERLING, ILL., ASSIGNOB TO THE STERLING SCHOOL-FURNITURE COMPANY, OF SAME PLACE.

IMPROVEMENT IN HINGE-JOINTS FOR SCHOCL-DESKS.

Specification forming part of Letters Patent No. 162,099, dated April 13, 1875; application filed February 18, 1875.

To all whom it may concern:

Be it known that I, CHARLES H. PRESBREY, of Sterling, in the county of Whitesides and in the State of Illinois, have invented certain new and useful Improvements in School-Desk Joints; and do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompan yin g drawings and to the letters of reference marked thereon, making a part of this specification.

The nature of my invention consists in the construction of a hinge-joint for school-desks, as will be hereinafter more fully set forth.

In order to enable others skilled in the art to which my invention appertains, to make and use the same, I will now proceed to describe its construction and operation, referring to the annexed drawing, in which Figure l is an outside view of the joint. Fig. 2 is a section of the same through the line 00 00, Fig. 1. Fig. 3 is an inside view of the joint with the interior plate removed. Fig. at is a view of said interior plate.

A represents a part of a school-desk standard, provided with the circular part B, to which the seat-arm C is to be hinged. The outer side of the circular part B is formed with a circular concentric recess in the center of which is a tapering hole. On the inner side, at the bottom of the circular part B, are formed shoulders to a, in which are made recesses to receive rubber bumpers. On the flange of the seat-arm C is formed a semicircular projection, b, with shoulder 61 at each end, and in the center of the circle is made a tapering hole corresponding with the hole in the circular part B of the standard. Through these holes is passed a tapering-headed bolt, 1), from the outer side inward, the head of the bolt being within the recess on the outer side of the circular part B of the standard. On the inner end of the bolt or plug D is formed a screw, h, as shown in Fig. 2. Over this end of the bolt is placed a plate or Washer, E, slotted at its lower end-and held by fitting over a lug, f, on the standard. The screw it projects through the plate E, and on the inner side of said plate, around the hole for the screw, is a circular recess to receive the end of the bolt or plug D. A nut, 'i, is then screwed on the end of the screw it to hold the parts in place.

It will thus be seen that the taperingbolt D is supported in the standard, and the plate and the seatarm turns on the bolt, and is supported in either position by the shoulders 61 and a.

It is well known that the seat-arm and stan dard of schoo -desks have been connected together by a trunnion; hence I disclaim any such connection as being any part of my invention. By means of the tapering bolt 1), I dispense with a trunnion and make the connection in such a manner that the bearing of the seatarm is upon the tapering bolt.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

The tapering bolt D, having the screw h, in combination with the part B of the standard, the seat-arm C, washer E, and nut i, all substantially as set forth.

In testimony that I claim the foregoing, I have hereunto set my hand this 22d day of January, 1875.

CHARLES H. PRESBREY.

Witnesses:

J. TYLER POWELL, O. L. Evnn'r. 

